CVE-2026-77555
High
Description
A malicious actor with access to the network could exploit an Out-of-bounds Write vulnerability found in certain UniFi gateway devices to execute a Denial of Service (DoS) attack on the device.
SeverityHigh
CVSS7.5
Exploit probability—
Product
UniFi Gateways
PublishedSep 22, 2026
First seenSep 22, 2026
Weakness typeCWE-787Out-of-bounds write
How to fix
Update
- Ubiquiti Inc UniFi Gateways5.1.26 or later
- Ubiquiti Inc Dream Machines5.1.31 or later
- Ubiquiti Inc Enterprise Firewalls5.1.31 or later
- Ubiquiti Inc Dream Routers5.1.31 or later
- Ubiquiti Inc Cloud Gateways5.1.31 or later
- Ubiquiti Inc Dream Wall5.1.31 or later
- Ubiquiti Inc Express4.0.21 or later
- Ubiquiti Inc Express 75.1.31 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Ubiquiti Inc UniFi Gateways | v < 5.1.26 | 5.1.26 |
| Ubiquiti Inc Dream Machines | v < 5.1.31 | 5.1.31 |
| Ubiquiti Inc Enterprise Firewalls | v < 5.1.31 | 5.1.31 |
| Ubiquiti Inc Dream Routers | v < 5.1.31 | 5.1.31 |
| Ubiquiti Inc Cloud Gateways | v < 5.1.31 | 5.1.31 |
| Ubiquiti Inc Dream Wall | v < 5.1.31 | 5.1.31 |
| Ubiquiti Inc Express | v < 4.0.21 | 4.0.21 |
| Ubiquiti Inc Express 7 | v < 5.1.31 | 5.1.31 |
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